From the beginning of exploration and settlement of Florida, the priests and missionaries who came to Pensacola were under the direct supervision of the Spanish Crown by virtue of the Royal Patronage of the Indies (Patronato Real de Indies) granted to Spanish Sovereigns by Pope Julius in 1508. Certain jurisdiction was, however, exercised by the Bishop of Santiago de Cuba, whose See was at Havana.

In 1703, Dionisio Resino, the oldest priest in Cuba, was named as the first auxiliary bishop of Florida, subordinate to the See of Santiago de Cuba. He did not arrive in St. Augustine until 1709, however, as the King, the Bishop, and the governor of Florida all argued as to how he was to be supported financially.

The last bishop to physically reside in Florida (though not by choice) before the British occupation in 1763 was the Bishop of Santiago de Cuba, Pedro Agustín Morell. Having been captured by the British in 1762 in Havana, he was taken to Charleston, South Carolina as a prisoner before being released and allowed to travel south to St. Augustine.

Within a year after Britain's occupation, no more than eight Catholics, all laymen, could be found anywhere in Florida, owing to the offer by Spain's King Charles III of homes in Mexico or Cuba to all his former subjects in Pensacola and St. Augustine who wished to leave.

In addition to Florida, Britain had also acquired eastern Louisiana from France in the first Treaty of Paris in 1763. By royal proclamation, the entire area was divided into two royal territories: East Florida, which extended from the Atlantic west to the Chattahoochee River, with St. Augustine as its capital; and West Florida, which extended west along the Gulf of Mexico from the Chattahoochee River to the Mississippi River, with Pensacola as its capital.

Even before the recapture of Pensacola by Spain in 1781, Bishop Echevarría, of Santiago de Cuba, had appointed a Capuchin priest from Louisiana, Father Cyril de Barcelona, to serve as vicario or vicar forane, over West Florida.

 Havana (1787 - 1793; 1806 - 1825) 

On September 10, 1787, the Holy See at Rome divided the diocese of Santiago de Cuba to form a new diocese of San Cristóbal, with its See at Havana. The mainland provinces of Louisiana and the Floridas, as well as the Cuban provinces of Santa Clara, Matanzas, Havana, and Pinar del Río, were placed under the jurisdiction of San Cristóbal. A Cuban priest, José de Trespalacios y Verdeja, was appointed as first bishop. Father Cyril de Barcelona was named auxiliary bishop of the Diocese of Lousiana and The Floridas, with residence in New Orleans.

Bishop Cyril undertook an official visitation of East Florida, arriving by ship in St. Augustine in July, 1788. During the next year, he conducted confirmations and other episcopal functions, interviewed the priests and residents, and conducted a census. Bishop Cyril remained in St. Augustine until June, 1789. In February 1791, he made a similar visitation to Pensacola in West Florida where he found depressing poverty.

 Louisiana (1793 - 1806) 

Pius VI, in 1793, created the Louisiana diocese, distinct from that of Santiago de Cuba. Luis Ignacio Peñalver y Cárdenas was appointed first bishop with New Orleans as his See city. The new Church of St. Louis was dedicated as a Cathedral and put into service on Christmas Eve, 1794. In addition to East and West Florida, the new diocese also extended over an area that stretched north and east to the Diocese of Baltimore, and south and west to Mexico.

Bishop Peñalver had difficulty getting priests to agree to go to Pensacola, writing that he "could not even get angels to go to Pensacola." He visited Pensacola in 1798 where he found the church in "pitiful condition" and was unable to persuade the people to make the necessary sacrifices for a new church, even though the "temporary" warehouse/church was slowly falling into ruin. There was only one priest in town, Father James Coleman, from the Irish College of Nobles at Salamanca.

The Louisiana Purchase in 1803 put the Pensacola church in a dilemma. Given the relationship of the Church and State in Spanish Colonies, it was impossible for Spanish West Florida to remain under the now American New Orleans Diocese. On September 13, 1806 an order came breaking all ties to New Orleans, and West Florida reverted to the Diocese of Havana under Juan José de Espada y Lander. Owing to the distance to Havana, the pastor of St. Michael, Father Coleman, was named vicario and ecclesiastical judge.

 Mobile (1825 - 1968) 

The year 1821 saw Spain relinquish control of the Floridas to the United States, removing government control from the church. With no church official willing to assume responsibility for the poverty-stricken territory, a solution was not reached until June, 1825. At that time, Florida and Alabama were erected into a vicariate-apostolic with Father Michael Portier of New Orleans as bishop.

Bishop Portier landed in Mobile on December 20, 1826, and discovered that, although his territory seemed huge, the only three churches were in St. Augustine, Pensacola and Mobile. Then the Mobile church burned in 1827, and a rough-built structure was hastily constructed to replace it. Bishop Portier began his administration by riding through his vicariate from Pensacola to Tallahassee and St. Augustine, and back again, offering the Holy Sacrifice, preaching, and administering the Sacraments as he went. He traveled amid great hardship and hostility, seeking to strengthen the Church across North Florida. He sailed for Europe in 1829 in quest of assistants and, returning with two priests and four ecclesiastics, found the vicariate raised to the Diocese of Mobile.

One seminarian who attended the Bishop's installation ceremony wrote a shocked letter home to France in which he described the Mobile church as "a poor wooden barn." The "cathedral" was a little church twenty feet wide by fifty feet deep, the official residence a still smaller two-roomed frame structure. Finally, in 1850, the Cathedral of the Immaculate Conception was consecrated for public worship; however, it remained far from finished on the inside, the windows consisting of clear glass with only the borders boasting color.

By that year, there were churches and congregations in Mobile, Spring Hill, Summerville, Mount Vernon, Fish River, Pensacola, Tuscaloosa, and Montgomery. Bishop Portier was somewhat relieved that same year by the detachment of the eastern portion of Florida (East of the Apalachicola River) and its annexation to the established Diocese of Savannah with Bishop Francis X. Gartland, first Bishop. The ten western counties of North Florida remained in the Diocese of Mobile.

Bishop Thomas J. Toolen became Sixth Bishop of Mobile in 1927 and guided the Church in Alabama and Northwest Florida for more than forty years, traveling extensively by automobile and establishing numerous parishes, schools and institutions. Pensacolians were shocked, then, to learn that West Florida was to be separated from the Diocese of Mobile, after 142 years, and attached to the Diocese of St. Augustine. The "change of command" took place in June, 1968, in St. Michael Church when Archbishop Toolen relinquished this portion of the Diocese of Mobile to Bishop Paul F. Tanner of St. Augustine.

 St. Augustine (1968 - 1975) 

On September 8, 1565 a small band of Spaniards celebrated Mass on the shores of Eastern Florida in preparation for starting a settlement there. They named their new home St. Augustine in honor of the saint on whose feast day they sighted land.

In 1870, that portion of Florida east of the Apalachicola River that had been removed from the Diocese of Mobile and placed in the Diocese of Savannah, was once again carved out and designated as part of the newly created Diocese of Saint Augustine. Bishop Agustin Verot was named First Bishop and participated in the First Vatican Council.

In 1968, Pensacola and West Florida became a part of the Diocese of St. Augustine under Bishop Paul Francis Tanner, even though there was a 400 mile distance between the two cities. Seven years later the new Diocese of Pensacola-Tallahassee was erected in 1975.

 Pensacola-Tallahassee (1975 - present) 

The Diocese of Pensacola-Tallahassee was established on November 6, 1975. It was formed out of the ten counties west of the Apalachicola River that had formerly been a part of Diocese of Mobile, prior to being incorporated into the Diocese of St. Augustine in 1968, and eight counties east of the river that had been a part of the St. Augustine Diocese from its establishment in 1870.

The resulting 18 county diocese, covering 14,044 square miles, currently has a Catholic population of 62,545, or approximately 5% of the total population of the area. The Catholic population is most numerous in the western (Pensacola) section of the diocese where 40% of the total population lives. The remaining 60% are nearly equally divided in the areas of Fort Walton Beach, Panama City, and Tallahassee. There are seven rural counties along the 200-mile stretch of highway from the Cathedral of the Sacred Heart in Pensacola to the Co-Cathedral of St. Thomas Moore in Tallahassee.

There are forty-eight parishes and nine missions served by forty-nine priests and sixty-five deacons. Of the seven dioceses now in Florida, the Diocese of Pensacola-Tallahassee is the most extensive in size and yet the least populated.